Electromagnetic machines such as electric motors and generators are useful in converting one form of energy to another form of energy (e.g., converting electrical energy to mechanical energy or converting mechanical energy to electrical energy). A typical electromagnetic machine may include a stationary component, or stator, and a rotating component, or rotor, that rotates relative to the stator. The relative rotation of the two components results in energy conversion.
One example of an electromagnetic machine is an alternating current (AC) induction motor. In an AC induction motor, current flow in conductors supported on the stator produces a rotating magnetic field. The magnetic field induces a current in closed loop conductors in the rotor resulting in a magnetic force that causes the rotor to rotate relative to the stator. In a typical AC induction motor, the closed loop conductor is commonly called a squirrel cage and includes a plurality of conductor bars extending parallel to or at a skew angle relative to the rotational axis of the rotor and rings disposed at either end of the bars and rotor and electrically coupling the bars together. The formation of the rotor, and particularly the squirrel cage, has a significant impact on the performance and cost of the machine.